Method for heating liquid heat carrier and a device for carrying out said method

ABSTRACT

The proposed heating method includes supplying a liquid heat carrier to a heating area by means of turning it about the cylindrical surface of a heater in such a way as to form an axially symmetric swirl flow, the trajectory of each heat carrier particle being tangent to the surface of the heater the temperature of which is higher than the critical thermal point of the heat carrier. The heating device contains a heat exchanger having a cylindrical body, tangentially positioned pipes for supplying the cold heat carrier and pipes for discharging the hot heat carrier. The heater having a cylindrical surface is coaxially arranged in the cylindrical body. The heating device contains an expansion tank, binding pipes and heat exchangers. The temperature of the heater is controlled by means of thermocouples. An electric heat source (a resistance helix) is located in the heater. The heating device has a high efficiency of heat transfer from the heater to the heat carrier due to the double phase transition: water-steam-water.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Phase application of PCT/RU2008/000379,filed on Jun. 18, 2008, which claims priority to Russian PatentApplication no. 2007125918, filed on Jul. 9, 2007, which areincorporated herein by reference in their entirety.

FIELD OF THE INVENTION

The invention relates to heat power engineering, and more particularlyto hot steam generation for industrial and individual needs, as well toconstruction of heating systems.

DISCUSSION OF PRIOR ART

A method of evaporation of liquid in the channel by means of heating itover the steam saturation point is known (see U.S. Pat. No. 3,326,640,issued in 1967). The disadvantages of the method described therein are alack of reliability and high materials consumption caused by the need toincrease liquid pressure.

A method of evaporation of liquid by heating it in a channel above thesteam saturation point, decreasing the pressure in the liquid andmaintaining the temperature of the channel walls below the limit ofsuperheat of the evaporated liquid is known, where the heat output ofthe channel increases by means of imposing current collecting electricpotential on the channel walls (see Russian Patent No. 2128804,published on Apr. 10, 1999). The disadvantage of this method isinefficiency of the evaporation process and complexity of commercialapplication.

A method of steam generation is known (see Russian Patent No. 2293913,published on Feb. 20, 2007) where a boiler is filled with water up to arequired level, and electric voltage is applied to the water by means ofelectrodes positioned in the water. The electric voltage is applied tothe water by using high voltage pulses, and water jets that appear uponelectric voltage application are dispersed structure by flowing waterjets through a splitter, which is a system that hinders water jets. Theefficiency of heat output from the heater to the heat carrier in saidmethod is also low.

A method of steam generation described in SU 419687, published on Mar.15, 1974, is known. An operating environment heated up to thetemperature lower than its saturation point under current pressure issupplied to an inlet chamber, where the environment is then swirled. Atthe starting point, the speed of the environment increases and thepressure decreases. The environment moving towards a diaphragm the swirlrange decreases in speed, and the environment pressure becomes equal tosaturation pressure at this temperature. Steam bubbles affected bybuoyancy forces collect in the center and are delivered to a consumer.The disadvantage of this method is also a lack of efficiency of heattransfer from the heater to the heat carrier.

A direct-flow water heater, described in SU 663982, published on May 25,1979 is known, which contains a body with a central combustor enclosedin a water jacket and a peripheral ring-shaped catalyst chamber. Thedisadvantage of such water heater is poor distribution of gases comingout of the catalyst chamber and low efficiency of the device.

A direct-flow surface water heater, described in SU 787812, published onDec. 20, 1980 is known, which contains a body, a burner device connectedto the combustor, which is enclosed in a water jacket with a ring-shapedcatalyst chamber located around the water jacket and connected to thecombustor with its bottom side, and to a pipe for discharge of exhaustgases with its foreside, by means of a ring-shaped demister above whicha ring-shaped diaphragm with valves is arranged. This device also has aninefficient transfer from the heater to the heat carrier.

A method of liquid heat carrier heating and a device for carrying outthis method are known (see Russian Patent No. 2178125, published on Jan.10, 2002). The liquid heat carrier heating method described thereinconsists of supplying a liquid heat carrier to a heating area in aheating device body from a heat source, heating the heat carrier anddischarging the heated heat carrier from the heating area. The liquidheat carrier is supplied from above to the heating area on the spinningshell ring, thus forming a thin-film liquid sheet of the heat carrier.The heated heat carrier is then discharged on the underside of thespinning shell ring, and in the body of a heating device hot exhaustproducts are organized to force the flow around the shell ring from theheat source, on the inside and outside surfaces of the shell ring withthe combustion products being drawn off of the body of a heating device.

In this method and a device for carrying out the method, the spinning ofa shell ring causes forming of condensed flow of liquid heat carrier onthe walls of the shell ring, and the direct heating is made by means ofinfrared radiation and hot fuel combustion products from the heatsource, while the rate of interior pressure in the heat carrier, whichis effected by centrifugal force is chosen depending on the rate of thering shell spin, so as to ensure the heating and the discharge of theheat carrier with a temperature above its boiling point under airpressure. The disadvantage of this method and the device for carryingout the method is low efficiency of heat transfer from the heater to theheat carrier.

Hence, there is a need to develop new methods for heating liquid heatcarriers and devices for carrying out these methods with a highefficiency heat transfer from a heater to a heat carrier.

DISCLOSURE OF EMBODIMENTS OF THE INVENTION

The objective of this invention is to create a method to increase theefficiency of heat transfer from a heater to a heat carrier, to increasethe reliability of the device for carrying out this method, to simplifyits design and at the same time to increase its productive capacity.Other achieved objectives and advantages of this invention will be shownbelow when briefly describing the drawings figures in preferredembodiments.

The method of heating a liquid heat carrier includes supplying a liquidheat carrier to a heating area in a heating device body from a heatsource, heating the heat carrier and discharging the heated heat carrierfrom the heating area. In order to increase the efficiency of heattransfer from the heater to the heat carrier the supplying of a liquidheat carrier to the heating area is made by means of turning it about acylindrical surface of the heater, thus forming an axially symmetricswirl flow, the trajectory of each heat carrier particle being tangentto the surface of the heater whose temperature is higher than thecritical temperature of the heat carrier.

Heating the heat carrier in accordance with claimed invention is doneusing a double phase transition, which comprises a first transition fromliquid to steam and a second transition from steam to liquid, i.e.evaporation and condensation in one free range of a heated liquidmolecule (particle).

In order to turn the heat carrier, it is preferentially supplied on theunderside of the heating device through at least two pipes tangentiallypositioned and forming the force couple. The heat source is preferred tobe electric heating or natural gas burning.

To organize an ascending path of flow it is preferred to observe theformula:

(m _(T) T _(T))/sec≦(m _(n) T _(n))/sec,

where m_(T) is the heat carrier weight;

T_(T) is the heat carrier temperature;

m_(n) is the heater weight;

T_(n) is the heater temperature.

The objective is fulfilled by means of a heating device that switches aheater with a heating source, a heat exchanger with pipes for supplyingthe cold heat carrier and for discharging the hot heat carrier. Theheater having a cylindrical surface is coaxially arranged in the heatexchanger that has a cylindrical body, in order to supply the heatcarrier on the underside of the body at least two pipes are arrangedtangentially positioned to form an axially symmetric swirl flow, and atthe top of the cylindrical body a discharge of the hot heat carrier isarranged.

The heating device preferably includes an expansion tank, binding pipesand a heat exchanger. For supplying the hot heat carrier it is preferredto arrange at least two pipes at the top of the cylindrical body.

In the described method, the temperature of the heater surface is higherthan the critical thermal point of the heat carrier. The heater surfacethat has a temperature over the critical thermal point of the heatcarrier (water) is immediately surrounded by a steam sheet (steamjacket), and heat transfer slows down considerably. In case of usingwater as a heat carrier, the critical thermal point of water is 374.15°C. Keeping in mind the high speed of steam molecules free range (up to500 m/sec) and extremely short free range, this method suggests toorganize the heat carrier flow in such a way as to make liquid watermolecules turn to steam when touching the cylindrical surface of theheater, and having their motion path immediately changed, joining theorganized flow of liquid heat carrier (water). The energy ofvaporization is given up to the heat carrier during condensation (doublephase transition), and the following molecules of the liquid heatcarrier (water) and of the resulting (water) steam may follow theorganized trajectory of flow.

The heating device has high efficiency of heat transfer from the heaterto the heat carrier by means of double phase transition:water-steam-water (specific heat of water is 4.19 J/g*K at 20° C.,specific heat of evaporation is 2255 J/g).

BRIEF DESCRIPTION OF THE ATTACHED DRAWINGS

FIG. 1 displays the main view of the heating device;

FIG. 2 displays a A-A sectional view of the device of FIG. 1.

The heating device includes a heat exchanger having a cylindrical body1, tangentially positioned pipes for supplying the cold heat carrier 2,and pipes for discharging the hot heat carrier 3. The heater 4 having acylindrical surface is coaxially arranged in the cylindrical body 1. Theheating device includes an expansion tank 5, binding pipes and heatreceivers 6. The device can be supplied with an electric powerdistribution box and an automatic control system 7. The temperature ofthe heater 4 is controlled by means of thermocouples 8 arranged in theheater 4. An electric heat source (a helical resistive element 9) islocated inside the heater 4.

The system being filled with the heat carrier the heater 4 is heatedover the critical temperature. Due to its physical properties the heatedliquid flashes to the expansion tank 5 and the cold heat carrier issupplied to the heating area due to the flow continuity by means offorming an axisymmetric (axially symmetric) swirl flow, the trajectoryof each heat carrier particle being tangent to the surface of the heater4 the temperature of which is higher than the critical thermal point ofthe heat carrier. An axially symmetric swirl flow arises because thesupply of the cold heat carrier is done through at least two tangentialpipes, and due to this the heat carrier swirls in the device body.Depending on the power of the installation, more than two tangentialpipes for supplying the cold heat carrier may be used or a guidingdevice may be implemented. Any known device for heat carrier swirlingcan be used as a guiding device.

When touching the surface of the heater, the heat carrier is quicklyheated and it evaporates. Once it gets into the swirl flow of the heatcarrier, the heat carrier condenses inside the flow, giving up its steamcondensing energy to the heater. Once that happens, the heat carrier isheated and the heat carrier flows. The discharge of the hot heat carrieris carried out through the discharge pipes 3 in order to maintain thecoaxially organized heat carrier flow in regard to the heater 4. Anyknown heat source that is used for these purposes can be used for theheater 4.

The heating device operates as follows:

The heat carrier (water) is poured in the heat exchanger 1 through theexpansion tank 5 or a special feed line (not shown in FIG. 1). Thetemperature of the heater 4 is raised in any known way (using electricheating or fuel combustion heat). The density of the heated heat carrierdecreases. The heat carrier having a form of cylinder H around theheater 4 starts rotary motion under condition of the continuity of flowthat makes room for supplying the cold water through the tangentialpipes 2. The heated heat carrier discharges through the discharge pipes3 to the receiver 6. In the receivers 6 the heat carrier flow is cooledand the heat carrier returns to the heat carrier supplying pipes 2 ofthe device.

THE PREFERRED EMBODIMENT

The preferred embodiment is shown in FIG. 1 and FIG. 2. To swirl theheat carrier, it is supplied on the underside of the heating devicethrough the two pipes 2 tangentially arranged and forming the forcecouple. The electric heat can be used as a heat source. The heater alsoincludes an automatic control system 7. To discharge the hot heatcarrier, two pipes 3 are arranged at the top of the cylindrical body.

To organize an ascending path of flow the following formula is observed:

(m _(T) T _(T))/sec≦(m _(n) T _(n))/sec,

where m_(T) is the heat carrier weight;

T_(T) is the heat carrier temperature;

m_(n) is the heater weight;

T_(n) is the heater temperature.

When using the proposed heating device for room heating, a pump is notneeded, because the heater 4 can rise the water temperature up to thecritical point (T=374.15° C.) and further, up to the heater temperature.

Claimed solution results in the increase of efficiency of heat transferfrom the heater to the heat carrier, the increase of reliability of thedevice and the simplification of its construction.

INDUSTRIAL APPLICABILITY

The device described herein can be used in, e.g., heat power engineeringand can be used in different liquid heating systems, particularly waterheating systems.

1-7. (canceled)
 8. A method of heating a liquid heat carrier, the method comprising: supplying the liquid heat carrier to a heating area in a heating device body from a heat source; in the heating area, turning the liquid heat carrier about a cylindrical surface of the heater, thereby forming an axially symmetrical swirl flow, wherein a trajectory of each heat carrier particle is substantially tangential to the cylindrical surface of the heater; maintaining a temperature of the cylindrical surface higher than a critical temperature of the heat carrier; and discharging the heated heat carrier from the heating area.
 9. The method of claim 8, wherein the liquid heat carrier is supplied on an underside of the heating device through at least two pipes, the two pipes being tangentially arranged and forming a force couple.
 10. The method of claim 8, wherein electrical heating is used as a heat source.
 11. The method of claim 8, wherein gas combustion is used as a heat source.
 12. The method of claim 8, wherein an ascending path of the axially symmetrical swirl observes the following formula: (m _(T) T _(T))/sec≦(m _(n) T _(n))/sec, where m_(T) is the heat carrier weight; T_(T) is the heat carrier temperature; m_(n) is the heater weight; T_(n) is the heater temperature.
 13. A heating device comprising: a heater with a heat source; a heat exchanger having at least two pipes supplying cold liquid heat carrier; at least one hot liquid heat carrier discharge pipe; the heat exchanger having a cylindrical body with a cylindrical surface coaxially arranged with the heater, the heat exchanger supplying the cold liquid heat carrier on the underside of the cylindrical body through the at least two pipes; the at least two pipes being positioned tangentially to form an axially symmetrical swirl flow, and wherein a discharge of the hot liquid heat carrier is from the top of the cylindrical body.
 14. The heating device of claim 13, further comprising an expansion tank, binding pipes and a heat receiver.
 15. The heating device of claim 13, wherein, at a top of the cylindrical body at least two pipes are arranged for hot liquid heat carrier discharge. 